L (disambiguation)

L, or l, is the twelfth letter of the English alphabet.

L or l may also refer to:

Units of measurement and currency

 * L, Langmuir (unit), a unit of exposure to a surface
 * L, length in general (often the longest dimension, as opposed to width, height, or depth)
 * Horse length, used in horse racing
 * Boat length, used in rowing
 * L, l or ℓ, litre unit
 * Ancient Roman libra (translated as "pound"), a weight measure with derivative units denoted with "L" or a derived character:
 * Pound (currency), a number of currencies from the British Empire, abbreviated £ or (historically) "l", "L", or "$$\mathfrak{L}$$". (Some fonts use a two-bar version resembling the lira sign ₤.)
 * Livre (disambiguation), a number of currencies from the French Empire, with the original abbreviated "£", "₶", or "lt"
 * Lira, a number of currencies from Italy and the Ottoman Empire, abbreviated as ₤
 * Leaf (books) ("l." or ℓ), an alternate numbering for books, in contrast to "p." for pages
 * Specification for a line of text, for example "l. 3" is the third line of text

Mathematics

 * L, constructible universe, a particular class of sets which can be described entirely in terms of simpler sets
 * L-function
 * Laplace transform
 * $$\mathcal{L}$$, likelihood function
 * ℓp space, the space of sequences with a finite p-norm
 * Lp space, a function space defined using a natural generalization of the p-norm for finite-dimensional vector spaces

Computing

 * L (complexity), a complexity class in computational complexity theory
 * L-notation, a notation for running times of subexponential algorithms, often used in number theory
 * L – A Mathemagical Adventure, a 1984 computer game
 * Android L, code name for Android Lollipop

Physics

 * Angular momentum
 * Inductance, the ratio of the magnetic flux to the current in an electrical circuit
 * Latent heat
 * Luminosity
 * Mean free path, the average distance traveled by a moving particle between successive collisions
 * Class L, a stellar classification
 * Galactic longitude (l), in the galactic coordinate system

Chemistry

 * l, abbreviation for liquid
 * Avogadro constant, in some German scientific literature
 * Leucine, an α-amino acid
 * L- prefix, a levorotatiory compound
 * Lewisite, a blister agent

Biology

 * Carl Linnaeus, in botanist author citations (L.)
 * Laelia, an orchid genus
 * Haplogroup L (Y-DNA)
 * Vertebra in the lumbar region of the spinal cord
 * ATC code L Antineoplastic and immunomodulating agents, a section of the Anatomical Therapeutic Chemical Classification System

Music

 * L (French singer), French singer-songwriter
 * L (South Korean singer), vocalist of Korean boy band Infinite
 * L Marshall, British singer credited as L on the Wretch 32 song "Traktor"
 * Lesure Number, music catalogue identifier for the compositions of Claude Debussy
 * L Number, classification of the compositions of Franz Benda according to the catalogue of Douglas A. Lee

Albums

 * L (Godley & Creme album) (1978)
 * L (Ayumi Hamasaki EP) (2010)
 * L (Steve Hillage album) (1976)
 * L (Candy Lo EP) (2008)
 * L (Moe album) (2000)

Vehicles and transportation

 * L (Los Angeles Railway)
 * Chicago "L", a rapid transit system in Chicago
 * L (New York City Subway service)
 * L Line (Los Angeles Metro)
 * Transilien Line L, a line of the Paris transport network
 * The official West Japan Railway Company service symbol for:
 * JRW kinki-L.svg Maizuru Line.
 * JRW oka-L.svg Uno Line.
 * L-plate, a plate for learning drivers under instruction
 * L Taraval (San Francisco Muni)
 * Nissan L engine
 * L, the low gear of an automatic transmission
 * LB&SCR L class, a British tank locomotive on the London, Brighton, and South Coast Railway

Companies and organisations

 * L. Inc., California-based corporation that makes organic personal care products
 * Liberals (Sweden), a political party in Sweden
 * Loews Corporation, by NYSE ticker symbol
 * Miscellaneous, when used as the fifth letter or behind-the-dot notation on the NASDAQ and NYSE ticker symbols

Language and literature

 * 50 (number), in Roman numerals
 * [ʟ], the velar lateral approximant (IPA notation)
 * [l], the alveolar lateral approximant (IPA notation)
 * The "low" or common language in a diglossia
 * $$\mathfrak{L}$$, a siglum for the Vetus Latina version of the Bible
 * L (novel), a 1999 novel by Erlend Loe
 * L (Death Note), a character from the Death Note manga series

Places

 * L postcode area, for Liverpool
 * L Island, former name for Scawfell Island, Queensland, Australia
 * L, the military time zone code for UTC+11:00

Other uses

 * Lucius (praenomen), a Roman praenomen
 * Left (direction)
 * L, a rating of the Brazilian advisory rating system
 * L (film), a 2012 Greek film
 * Lucifer (2019 Indian film), abbreviated simply as L
 * L, production code for the 1965 Doctor Who serial The Rescue
 * Canon L lens
 * Latina Televisión, a Peruvian television channel
 * Internet slang for losing